California's demand for high-grade marijuana, whether it comes from dispensaries or the dude down the street, has led to a high-dollar growing industry that some have said is the most valuable cash crop in the state.

A sad side-effect of the industry, however, is that the rare forest carnivore known as the fisher, a candidate to become an officially endangered species, is being killed by the harsh chemicals used by outdoor cannabis growers in California.

Not only that, but martens, spotted owls, and Sierra Nevada red foxes are threatened by the poison too:

This according to a new UC Davis study published in the latest edition of the scientific journal PLoS ONE.

Researchers discovered commercial rodenticide in dead fishers in Humboldt County near Redwood National Park and in the southern Sierra Nevada in and around Yosemite National Park.

Nearly 8 out of 10 of the dead fishers academics studied were exposed to the chemicals used on pot farms, they said. The poison also puts spotted owls, and Sierra Nevada red foxes at risk, researchers say.

The latest poisons can kill a fisher in one dose, according to the UC Davis findings.

Now, you could try to blame other kinds of non-organic farming, but researchers say they're not to blame:

The fishers, many of which had been radio-tracked throughout their lives, did not wander into urban or agricultural environments. However, their habitat did overlap with illegal marijuana farms.

More than 2,000 plants, along with "large amounts" of rodenticide, had been recently discovered, for example, 7.5 miles from their study area.

Spring, when fishers are rearing their young, is when pot gets planted and the poisons come out, unfortunately.

Lead author Mourad Gabriel of UC Davis Veterinary Genetics Laboratory, says that when fishers are harmed other animals will be too:

If fishers are at risk, these other species are most likely at risk because they share the same prey and the same habitat.